Dispenser for liquid additives to fluid streams



H LANG Jan. 19, 1965 DISPENSER FOR LIQUID ADDITIVES TO FLUID STREAMS 6 Sheets-Sheet 1 Filed Oct. 3. 1961 J 0 w 3:15 nflil- T W in "is :5 H m w I: :5: 2 ll ma fl nvvs-ron Helmut Lang Mestern,Ross ii Mestern Jan. 19, 1965 H LANG 3,166,096

DISPENSER FOR LIQUID ADDITIVES TO FLUID STREAMS Filed Oct. 3, 1961 6 Sheets-Sheet 2 A 7% my. 2

mvsuron Helmut Lang Me stern,R oss 8| Mestern H LANG Jan. 19, 1965 DISPENSER FOR LIQUID ADDITIVES T0 FLUID STREAMS 6 Sheets-Sheet 5 Filed Oct. 3, 1961 mvsrvroe Helmut Lang Mestern Ross 8 Me stern H. LANG Jan. 19, 1965 DISPENSER FOR LIQUID ADDITIVES T0 FLUID STREAMS Filed Oct. 5. 1961 6 Sheets-Sheet 4 mvsrvron Helmut Lang Mestern,Ross 8 Mestern Jan. 19, 1965 L 3,166,096

DISPENSER FOR LIQUID ADDITIVES TO FLUID STREAMS Filed 001:. 5i 1961 e Sheets-Sheet 5 mvzurm Helrnut Long Mestern,Ross 8 Me stern Jan. 19, 1965 v H LANG DISPENSER FOR LIQUID ADDITIVES T0 FLUID STREAMS Fil ed Oct. 3, 1961 6 Sheets-Sheet 6 INVENTOR Helmut Lang Mestern, Ross 8 Me stern United States Patent Ofiice 3,166,696 Fatented Jan. 19, 1965 Hehnut Lang, Wernieiten, S-iegsdorf, Upper Bavaria, Germany Filed 9st. 3, 1961, Ser. No. 142,695 Ciairns priority, appiicatien Germany, Get. 3, 1966, L 37,167; Mar. 22, 1961, L 38,528 22 Ciaims. (Ci. 137-5645) My present invention relates to a device adapted to introduce liquid additives into a main fluid stream at a predetermined rate proportionally related to the flow of that stream.

It is an object of my invention to provide means for introducing such additives inexpensively and reliably, with avoidance of complex machinery such as hydraulically or electrically operated pumps which need frequent servicing and require an external power supply.

It is another object of this invention to provide a device of this character responsive to but a slight pressure diflerentifl present in the main fluid stream, either as a result of a pre-existing obstruction (e.g. an attachment or a valve) in its conduit or by virtue of a con striction specifically provided therefor, for delivering the additive to the low-pressure side of the stream.

A further object or" the invention is to provide a device designed to limit the delivery of additive to a selected liquid and to prevent the inadvertent changing of ma terials admitted to the main stream.

It is also an object of the instant invention to provide an inexpensive disposable container for storing and transporting a liquid additive, the same disposable container serving as a reservoir during the subsequent injection into the main stream so that no transfer to another receptacle will be needed prior to utilization.

Still another object, allied with the preceding one, is to provide a container for storing, transporting and discharging a predetermined quantity of the additive without exposing it to the atmosphere, or to contact with the user, before its introduction into the fluid stream for which it is intended.

A more particular object is to provide means for securely preventing premature leakage of additive, especially in the case of liquids of high wetting power such as detergents, whereby the device will be adapted for use with household washing machines, dishwashers and the like.

Yet a further object of my present invention is to provide means for instantly indicating to the operator the impending or actual exhaustion of the additive container so that a new supply may be procured for substantially uninterrupted fluid flow.

In accordance with this invention I provide, essentially, a rigid vessel subdivided by a freely displaceable pressure-responsive member into two compartments of which one, containing the additive to be supplied, is connectable to the low-pressure or downstream side of the main conduit while the other is connectable to the high-pressure or upstream side thereof; advantageously, the downstream connection includes a checkvalve to prevent the backflow of main fluid into the vessel whereas the upstream connection is provided with adjustable throttle means for regulating the rate of additive outflow.

The freely displaceable pressure-responsive member consists, in accordance with a more particular feature of my invention, of a membrane (preferably of plastic material) of substantially infinite flexibility, i.e. one which does not offer a progressively increasing resistance to the driving force as would be the case with an elastic diaphragm. The membrane may simply span, with sufficentslack, the interior of the vessel; in many instances,

however, it will be more advantageous to make it an integral part of a collapsible bag originally containing the fluid to, be dispensed. The bag, and/or a Wall of the surrounding vessel defining'the additive compartment, is preferably pierced by a suitably channeled barb when the container is mounted in a holder having the necessary connections to the main conduit, the barb being fixed to the holder with its channel (e.g. a central bore) included in the connection to the downstream side of the conduit. As fluid from the upstream side of the conduit enters the initially empty expansible compartment separated from the additive compartment by the membrane, its relatively elevated pressure forces the additive from the dispenser into the downstream side of the conduit at a measured and preferably adjustable rate proportional to the existing pressure differential and, therefore, to the flow of the main stream.

If the rigid vessel surrounding the membrane-protected additive is part of the disposable container, its removal from the holder upon exhaustion of its contents will enable the immediate substitution of a full new container. Such disposable vessel need not be very strong if the holder is designed as a receptacle into which the vessel is inserted with close fit so as to be reinforced thereby against the fluid pressure acting upon its interior during the dispensing operation. If, on the'other hand, only the bag-forming membrane is disposable and the vessel forms part of the permanent dispenser installation, then the costs of replacement will be reduced but this advantage will be at least partly balanced by the need for draining the vessel after the removal of each spent bag.

Generally, no harm will come from a possible penetration of the compartment-separating membrane by the piercing device or barb after the additive has been exhausted; in such event part of the liquid from the conduit will merely flow through the bypass thus created and will rejoin the main stream at the outlet of the dispenser. If it is desired, however, to prevent such piercing of the membrane or the bag portion originally remote from the outflow orifice, then the piercing device must be so designed as to penetrate only the proximal container Wall; for this purpose it is desirable to provide the container, on the side facing the piercing device,.with a reinforced necl: forming a passage originally spanned in its interior by a frangible diaphragm, the barb rupturing the diaphragm upon the mounting of the container but remaining .concealed within the passage. In this case it is also possible to utilize the subsequent blocking of the passage by the collapsed membrane, and the resulting rise in the pressure of the upstream compartment, as a means for actuating "a signaling device to indicate the emptying of the dispenser.

Means may be provided on the pierceable end of the container for guiding the barb in a positive manner and preventing the spillage of additive outside its channel,

especially in the case of detergents and other leakage The container may for this purpose be. rigid with an outwardly projecting flange, advantageously equipped with a bayonet coupling or the like for connectprone liquids.

ing it to the holder, which forms a seat slidably receiving the barb with good all-arou|nd contact. If the container comprises a bag integral with the membrane, both the bag and the flange may be made from heat-scalable plastic material adapted to be firmly bonded together by fusion. My invention, in accordance with another of its features, also provides a particularly advantageous elec- 1 trode for producing an annular seam for this purpose, this 1 electrode including a projecting ring of resistance material adapted to be heated substantially uniformly by current traversing it in radial direction .over its entire circumference.

The above and other objects, features and advantages of the present inventionwill become more fully apparent from the following detailed description, reference being i made to the accompanying drawing in which:

FIG. 4 is an axial cross section of another embodiment;

FIG. 5 is a top viewof the de'viceshown in' FIG; 4; FIG. 6 is a view similar to PEG. 4 of a further modifica- 7 tion; FIG. 7 is a partly diagrammatic view, generally similar to FIG. 1, of still another embodiment;

FIG. 8 is a fragmentary sectional dctail view of an additive bag adapted to be used in a system of the type shown in FIG. 4; V

FIG. 9 is a partial top view of the bag shown in 8;

FIG. 10 is a cross-sectional view of a circular heating element for producing the bag of FIGS. 8 and 9;

FIG. 11 is a schematic view of a System'comprising .exhaustion-indicating. means in combination with a dispenser'of the type shown in FIG.- 7; 7

FIG. 12 is a' cross-sectional view of a modified indieating or signaling device for the system of FIG. ll;

FIG. 13 is a bottom View of the heating element shown in FIG. 10, takenon the line Xlil-Xlli thereof; and

FIG. 14 is an enlarged sectional view taken on the line XIVXlV of FIG. 13. a

'As can be seen from FIG. 1, a can-shaped container 11 is removably mounted in a frame 12 between two plates 13 and 14; The lower bearing plate 13 is securely affixed to the lower member 15 of the frame 12 and has within it a circular gasket 16 on which lies the lower rim or" container 11. The bearing plate 13 has also abarb 18 whose conical point 19 punctures the bottom 26 of the container 11 when it is placed in the fixture so that additive fluid re-.

" plate 14 further has a fitting 28 that opens into a cavity 29 on the lower face of the plate. The cover 36 of the container 11 has holes 31 through which fluid-from the cavity 29 enters. The fluid comes from the region of higher pressure ahead of the constriction 35 in the fluid line 34, throughthe feed line 32 and the shut-off valve 33 which also serves as a flow regulator. The channel 22,

the additive contained under the membrane 21 is expelled and the membrane 21 lies on the bottom 26. Then the user merely lifts the retaining plate 14, removes the container. 11 (now filled with fluid from the conduit 34) from the holder 12 and substitutes a new container filled with additive. The insertion of a new container 11 can thus be accomplished simply an rapidly through suitable manipulation of spindle?! FIG. 2 shows a modified container 11' in which, for the purpose of insuring a more complete outflow of additive,. the channeled piercing head 19" of the barb 18' is displaced 'on the lower plate 13 to the rim'17' of the container 11. Furthermore the frame 12' is retained in a fixture 42 by bolts 42 in such manner that this frame 23 of herb 18 is'connected with the main fluid stream 34 below the constriction 35 by a feed line 36, a checltvalve 37, and a nozzle 38.

I Thedifference in pressure ahead of and behind the constriction 35 in the line 34 causes fluid from the main stream to enter the cavity 29 in the retaining plate 14 and from there to pass into the upper compartment 39 ontop of the membrane 21 so as to drive out the additive. fluid from its lower compartment, within the membrane 2-1, through the feed line 36 into the main line 34.

tive.

between the bottom and the sidewalls thereof so that the additive can escape only through a hole pierced in the bot-tom 2i]. 39 in the container 11 over the membrane 21 fills up more 'In operation the expanding compartment and more with the fluid from the line 34 until finally all interior of receptacle 191. A relief valve .115 in cover venient opening and closing of the vessel.

with the container 11' can be tipped into the positions indicated in dotted lines. A soap 43 engageable by plate 13' limits the tilting motion.

With devices that are in continuous operation it is ad-' vantageous to have two additive containers 11a, 11b held in a common frame 51, as shown in PEG. 3, so that when one container is empty the second may be used. In this arrangement either container can be selected at will. This is accomplished by opening or closing the cut-off and regulating valves 52 and 53 which are representative of any conventional means, such as a three-way cock, for selectively shutting ofl line 54 or connecting it with either or" the containers.

When one second container is being used, the other if empty can be replaced preparatorily to being cut into the system at a later time.

A mochfied dispenser for introducing an additive into a fluid line comprises, as shown in FiGS. 4 and 5, a potshaped receptacle 11which is made pressure-tight by a cover 1%. A bayonet catch 103 is provided to simplify the'rapid opening and closing of the vessel. Sealing is accomplished by a slotted packing ring 194. The recessed inner bottom 165 of the receptacle 101 accommodates a barb 1% which pierces through the bottom 163 of the additive container 167, inserted with limited peripheral clearance into the receptacle 101 which serves as a reinforcing vessel therefor, and pierces the proximfl portion of the flexible membrane N99 forming a closed bag around the additive.- The additive is released through thes hole 111) in the barb 106. 'The barb is surrounded by a packing ring 111 which serves as a seal between it and the bottom 168 of the container 197. A compression spring 112 in the bottom 165 of the receptacle 101 ejects the container 107, upon the removal of cover 192, to simplify itsreplacement.

sure that the container 187 is pressed firmly against the barb 1% and the surrounding packing ring 111, an adjustable abutment screw 113 (which could also be replaced by a resilient member similar to spring 112) is provided on the underside of the cover 1652. Below the bottom 165 there is attached to it a fixture 114 with fittings for the feed lines extending to locations upstream and downstream of the constriction in the main fluid line, and with corresponding connections leading to the 1112; can be opened and closed by a shoulder 116 on the end of an axially slidable rod 117 that is attached to a handle 118. The handle is provided for rapid and con- When the handle 113 is pulled out preparatory to removing or locking the cover 162, the shoulder 116 on rod 117 depresses a pin 119, thereby opening a valve 123 in a venting channel 122 which connects the space under the cover 102 to'. the outside atmosphere. When the handle 118 is returned to an intermediate position, a spring 126 restores the valve 123 to its normal closed position. This valve prevents a pressure buiildup in the receptacle when the cover is replaced, yet prevents the escape of fluid to the atmosphere.

Fluid from the main stream enters the interior of the vessel 1111 through fixture 114 by way of a port 125 and In order to :as

, just described is shown in FIG. 7.

109. The additive exits through the hole 110 into the fixture 114 and thence reaches the region of low pressure below the constriction in the main fluid line where 1t mixes with the main fluid stream.

Another embodiment of the device is shown in FIG. 6. Here the membrane itself constitutes the container 71 and is inserted into a pot-shaped vessel 72 which can be closed by a cover'73. A shell 12, to which the vessel 72 is permanently secured via a pad 126, has recesses to receive lugs 74 projecting radially from cover 73 for centering the latter. An annular gasket 1% is compressedbetween vessel 72 and cover 73 when the lugs 74 are clamped down by a screw cap 127. The neck 75 of the additive bag 71 is placed over a nipple 76 which passes freely through cap 127 and contains a channel for the exit of the dispensed fluid. The nipple 76, terminating in a barb 77, is connected by a flexible feed line 78 and a checkvalve (not shown) with the downstream side of the main fluid stream. The receptacle 72 has an orifice 79 in its bottom which can be connected, through a three-position cock 84), with a feed line 82 and the upstream side of the main fluid stream in order to admit the fluid thereof into the interior of the vessel 72, in order to expel the additive, or with a drain 81 through which the displacement fluid can be removed when a refill container of additive is inserted; the third position serves to block the orifice 79.

Another embodiment of the invention similar to that It comprises a vessel 131 with a top 132 that forms a pressure-tight seal with a vessel 133 removably depending thereform. The vessel 133 is shown threaded to top 132 although a bayonet coupling, e.g. as shown in FIG. 4, may of course also be used. The top 132 has a threaded nipple 134- terminating in a barb 135. The reinforced neck'136 of a collapsible plastic container 137 of additive is screwed onto the nipple, thus causing the point of the barb 135 to penetrate a frangible sealing diaphragm 138 which lies somewhat recessed in a passage leading to the interior of the additive container 137. This permits the contents of bag 137 .to escape through the center channel 139 of nipple 134. The feed line 142. from the region of high pressure ahead of the constriction 144 in the conduit 145 opens into the interior of the bag 137 through a port 141'; The additive leaves the container 137 through an adjustable nozzle 146, a checkvalve 147, and a feed line 143. It then proceeds to the region of low pressure 149 below the constriction 144. Nozzle 146 can be adjusted by moving the needle valve 153 axially'by means of a knob 151.

This device is particularly well adapted for use with small washing machines or household dishwashers in which a measured quantity of rinsing or wetting agent is to be put into a water bath in a receptacle 152. This is accomplished by the opening of an electrical or similar valve 153 actuated by the pressure difference in front of and behind the constriction, thus admitting water into the interior 140 of the vessel 133 and expelling a proportional quantity of the additive from the container 137 into the water bath through feed line 145.

FIGS. 8 and 9 show a detail of a collapsible bag which is advantageous in the case of strongly wetting additives and is particularly adapted for use with the device shown in FIGS. 4 and 5. The additive fluid is contained in a bag 61 which is provided with a flange 62 having a pair of diametrically opposite projections 63 that can be inserted through cutouts 64 in the wall 65 (corresponding to bottom .168 of FIG. 4) and locked in place by a rotation of 90 degrees. The center opening 66 in the flange 62 has conical walls 67 to guide the piercing barb (not shown) into contact with bag 61. The walls 67 merge into an annular ridge 68 which snugly surrounds the ex- 6 terior wall of the barn after its insertion and assures a positive seal. The neck 62 is attached to the bag 61 by a circular heat seal 69.

In order to join the plastic bag 61 with the plastic flange 62 with an absolutely pressure-tight circular seam, 'itis advantageous to use an electric heating device 211 as shown in FIGS. 10, 13 and 14. This device 211- comprises an inner pole piece 212, of cylindrical configuration, surrounded by a massive ring 213, representing an strip 215, heating the latter evenly and permitting a perfect annular seal to be made, a firm bond ensues.

FIG. 11 illustrates a system for ascertaining the exhausted condition of a dispenser according to the invention. The dispenser 164, shown diagrammatically, may be generally similar to that of FIG. 7 and comprises a collapsible bag whose lower wall forms a reinforced neck only incompletely penetrated by the barb 179. A conduit 161serves to introduce water into a washing machine, not shown, via nozzles 196. The conduit 161 is divided by a constriction 162 into an upstream area 163, communicating via a connecting line 165, a shut-01f and regulating valve 195 and a port 197 with the interior of vessel 164, and a downstream area 166 communicating with the bore of barb 179 through a connecting line 167, a checkvalve 16S and a throttle valve, similar to regulator 151i, schematically indicated at 169. A branch line 176 leads from the entrance port 197 to a compartment 174 in an indicator housing 172 separated by a resilient membrane 173 from another compartment 175, i the latter communicating with the bore of barb 179 via a branch line 178. Indicator, 171 has a Window formed by a transparent wall portion 180 of its housing 172.

When the bag 1179 is fully collapsed, its upper wall portion 177 blocks the entrance to line 167. and the resulting pressure rise in vessel 164 is communicated to compartment 174. Membrane 173 is thereby pressed against window 180 where it becomes visible to the operator, the membrane for this purpose being preferably given a distinctive. coloring.

In the modified indicator 171 of FIG. 12 the housing 181 is transparent in its entirety and contains a cylindrical chamber'132 in which a membrane 183 doubled back into itself is secured to the chamber bottom 186 by an annular gasket 198 under pressure of a clamping ring 199 engaged by screws 2%. Nested in the membrane is a specially colored thimble-shaped indicating body 184 which is pressed against bottom 186 by a spring 185. The space 132 above membrane 183 is connected by a port 187 with the downstream region of the associated conduit through a line 188, while the space 189 between the membrane 183 and the bottom 166 is connected by a line 190 with the upstream region of the conduit. With the change in pressure caused by the closing of the outlet for the additive fluid, the pressure in space 189 increases and the indicator body 184 resting on the membrane ,is raised above the more slowly rising top edge 1910f the re-entrant membrane 183 so as to become partly visible through the transparent housing 181; membrane buzzer or other signaling device, not ShOWH,:tO indicate the need for replacing the depleted additive container;

I claim: i

1. A system for dispensing liquid additives into a fluid stream flowing in a conduit wherein a pressure differential exists between an upstream location and a downstream location, comprising a vessel, a receptacle for a lliquid additive removably mounted in saidvessel and having a movable wall member freely displaceable in said "vessel and subdividing the interior thereof into afir st compartment and. a second compartment,=said second compartment being constituted by said receptacle, piercing 'means on said vessel penetrating said receptacle, said :;piercing means having a channel communicating with the ssaid second compartment, said first compartmentbeing 'separated from said channel bysaid movable wall mem her and said secondcompartment-containing an additive Ito be dispensed, first connection means on said vessel forming a path for fluid from said upstream location to portion, said piercing means having a channel communieating with the interior of said vessel, a flexible membrane in said vesselsubdividing its interior into a first compartment separatedfrom said channel by said membrane and a second compartment open toward said channel, said second compartment containing an additive to' be dispensed, first connection means on said holder forming a :path for fluid from said upstream location to said first compartment, and second connection means on said holder communicating with said channel and forming a path therethrough for said additive from said second compartment to said downstream location.

3. A system according to claim 2 wherein said first connection means includes check valve means preventing ;a backfiow of fluid into said second compartment.

4. .A system according to, claim 2 wherein at least one of-said connection means includes throttle means for- 5. A system according to claim 2, wherein said vessel comprises a collapsible bag containing said membrane as an integral wall portion thereof.

6. A system according to. claim 2 wherein said holder comprises a frame with first and second relatively displaceable end plates, said vessel having first and second end walls respectively engaged by said first and second endplates upon a clamping of said vessel therebetween,

. said first and second end plates respectively having said first and second connection means terminating thereat, said first end wall being perforated for admitting fluid from said first connection means to the interior of said vessel, said second end wall being penetrated by said piercing means on said second end plate.

7. A system according to claim 6 wherein said piercing means is eccentrically positioned on said second endplate close to the periphery thereof, said second end Wall forming the bottom of said vessel, further comprising mounting means for said frame enabling the tilting there of into a draining position, said first and second connection means being flexible. I 8. A system according to claim2 member opposite said open end and alremovable cover member "overlying said open end in fluid-tight manner, one of said members carrying said piercing means.

9. A system according to claim 8, further comprising spring. means between said bottom member and said vessel for ejecting the latter from said receptacle upon removal of said cover member, the latter-being provided with abutment means bearing upon said vessel for stressing said spring means.

10. A system according to claim 8 whereinsaid vessel has'walls of insufficient rigidity to withstand the wherein said holdercomprises a receptacle with an open end, a fixed bottom' antennae internal pressure of said fluid, said receptacle closely surrounding. said vessel for reinforcing said walls;

11. A system according to claim 8 wherein said cover member has'a downwardly facing concavity receiving the top of said receptacle, said cover member being further-provided with normally closed valve means for venting said concavity.

12. A system according toclaim 11 wherein said cover member'and saidreceptacle are provided with mating coupling means interengageable upon relativerotatiou thereof,furtlier comprising handle means on said cover member for effecting said relative rotation, said valve means being operable by said'handle means.

13. A system according to claim 2 wherein said piercing means comprises a perforated barb, said vessel hav- I ing an inlet with a barb-receiving channel spanned'by 21 frangible element ruptured by said barb.

, 14. A system according to claim 13 wherein said inle is formed with an internal annular ridge snugly sur rounding said barb for substantially preventing leakage of said additive around said barb.

15. A system according to claim l4'wherein said vessel comprises a collapsible bag and an attachment therefor containing said inlet, said bag and said attachment consisting of thermally fusible material and being heatsealed to each other along a closed seam around said inlet, a portion of said bag encompassed by said seam being pierced by said barb.

16. A system according to claim 13 wherein said frangible element is recessed within said inlet, said barb terminating in said inlet. 7

17. A system according to claim 16, further comprising signaling means connected across said first and second connection means for indicating the depletion of said second compartment in response to a pressure rise in said first compartment due to a blocking of said inlet by said membrane.

18..A system according to claim 17 wherein said signaling means comprisesa housing, a diaphragm in said housing, and branch lines connecting the interior of said housing on opposite sides of said housing to. said firstand second connection means, respectively, said diaphragm being defiectable from a normal position by said pressure rise.

19. A system according to claim 18 wherein said hous- 3 ing is at least partly transparent for enabli ng observa-;

7 tion of a deflection of said diaphragm.

20. A system according to claim 19, further comprising an indicator body of contrasting color received in a re-entrant portion of said diaphragm and exposable to view upon an inversion of said re-entrant portion.

21. Avsystem according to claim 18, further comprising contact means carried by said diaphragm for closing an alarm circuit upon deflection of said diaphragm.

22. In a system for the proportioning of liquid additives into a fluid stream flowing in a conduit, in combination, means in said conduit for establishing a pressure differential between an upstream location and a downstream location therein, holder means, a vessel having yieldable wall portions receivable in said holder means and forming a flexible membrane subdividing said holder means into two compartments, spaced-apart plate means on said holder for clamping said vessel therein,

atleast one of said plate means being movable in the direction of the other plate means, a pointed cutting,

member on one of said plate means adapted to pierce said vessel upon displacement of said movable plate means against said vessel, said cutting member having a channel communicating with the interior of said vessel, and connection means forming a fluid path from said channel to said conduit at said downstream location and from said holder means externally of said vessel to said conduit at said upstream location whereby pressure of .fluid at said upstream location. forces said additive from said vessel through said channel into said conduit at said downstream location.

3/36 Guildford 137-5645 2/43 Baer 137-5645 Reasenberg 239-309 XR Mills 137-5645 Lacy Q. 137-5645 Pfefier 156-380 Stenbsrg 137-5645 Spunt 156-380 Laing 137-5645 XR M. CARY NELSON, Primar Examiner. 

1. A SYSTEM FOR DISPENSING LIQUID ADDITIVES INTO A FLUID STREAM FLOWING IN A CONDUIT WHEREIN A PRESSURE DIFFERENTIAL EXISTS BETWEEN AN UPSTREAM LOCATION AND A DOWNSTREAM LOCATION, COMPRISING A VESSEL, A RECEPTACLE FOR A LIQUID ADDITIVE REMOTABLY MOUNTED IN SAID VESSEL AND HAVING A MOVABLE WALL MEMBER FREELY DISPLACEABLE IN SAID VESSEL AND SUBDIVIDING THE INTERIOR THEREOF INTO A FIRST COMPARTMENT AND A SECOND COMPARTMENT, SAID SECOND COMPARTMENT BEING CONSTITUTED BY SAID RECEPTACLE, PIERCING MEANS ON SAID VESSEL PENETRATING SAID RECEPTACLE, SAID PIERCING MEANS HAVING A CHANNEL COMMUNICATING WITH THE SAID SECOND COMPARTMENT, SAID FIRST COMPARTMENT BEING SEPARATED FROM SAID CHANNEL BY SAID MOABLE WALL MEMBER AND SAID SECOND COMPARTMENT CONTAINING AN ADDITIVE TO BE DISPENSED, FIRST CONNECTION MEANS ON SAID VESSEL FORMING A PATH FOR FLUID FROM SAID UPSTREAM LOCATION TO SAID FIRST COMPARTMENT, AND SECOND CONNECTION MEANS ON SAID VESSEL COMMUNICATING WITH SAID CHANNEL AND FORMING A PATH THERETHROUGH FOR SAID ADDITIVE FROM SAID SECOND COMPARTMENT TO SAID DOWNSTREAM LOCATION. 